Bicycle lock



FIG. 1 is a perspective view taken from above and to the left of a bicycle lock showing my new design;

FIG. 2 is a top view;

FIG. 3 is a left side view;

FIG. 4 is a front view;

FIG. 5 is a right side view;

FIG. 6 is a back view;

FIG. 7 is a bottom view. 

The ornamental design for a bicycle lock, substantially as shown. 